Penn State presence made major difference in plum pox eradication

A plum pox-infected peach orchard is destroyed in 1999.

University Park, Pa.-- When plum pox was discovered in Adams County peach trees in October 1999 -- the first time the disease had been found in North America -- the nation's stone-fruit growers watched anxiously to see how Pennsylvania would respond. Thanks to quick action by state and federal officials, Penn State researchers and extension educators, and local growers, the virus was contained and eventually eliminated.

As the Pennsylvania Department of Agriculture officially lifted the quarantine of the area's stone fruit Oct. 29 -- certifying the state as plum-pox free -- James Travis reflected on the 10-year, collaborative eradication effort and the agricultural catastrophe it averted. The virus threatened to wipe out the state's $25 million annual production of peaches, plums, apricots, nectarines and cherries.

"It was an emotional time," recalled the professor of plant pathology in Penn State's College of Agricultural Sciences. "Although plum pox infects 100 million trees in Europe and cripples stone-fruit production there, it had never been seen in North America. Hardly anybody here had seen or heard of the virus. When growers realized what needed to be done to stamp out plum pox, they were apprehensive, and many looked to Penn State for advice."

The response was swift. Penn State researchers and extension specialists, officials and scientists from the Pennsylvania and U.S. departments of Agriculture, growers, legislators and citizens formed a rapid-response team to stop the spread of the virus. Special meetings were organized to bring growers and scientists together, and educational materials and a Web site were developed.

As a result, growers cooperated with regulatory officials to identify infected trees and destroy them. To assist producers with their financial loss, Penn State agricultural economists worked to develop impact costs, resulting in special state and federal funding to help these orchardists stay in business. Later, Penn State research showed how aphids spread plum pox, which is an important component in eradicating the disease.

The response to the threat posed by plum pox was also heart-breaking for growers. A stone-fruit quarantine area affecting four counties was established. Orchards where plum pox was found were destroyed -- trees pulled out of the ground, bulldozed and burned. Hillsides that should have been pink with peach blossoms were now bare, partially obscured by the smoke from burning trees.

"Imagine how they felt watching the trees they tended for years being destroyed," Travis said recently, speaking from the university's Fruit Research and Extension Center in Biglerville, where much plum pox research was done during the crisis. "There were orchard owners who would never have gone along with it unless the response team could reassure them that it was the right thing to do."

Travis said as the state's only land-grant university, Penn State, played a unique role in the eradication effort. "We could not have written a grant to respond to plum pox," he said. "We had to react immediately, and Penn State only could do that because we already had the research infrastructure and extension's history of working with the growers."

More than 1,600 acres of peach orchards eventually were taken out of production. A surveillance system was established that, over 10 years, tested more than 2 million samples in an effort to detect plum pox. (No positives have been seen in the last three years.) Affected growers were paid for their losses but not for the impact plum pox would have on their businesses with no guarantees.

"The strategy was risky -- nobody knew if it would work," Travis said. "All of the growers' sacrifice could have been for nothing.

"But we knew that we could not live with plum pox, that it would eliminate stone-fruit production in the East. We had to eradicate it. And it wasn't just about Adams County or southeastern Pennsylvania. Stone-fruit growers across the country were worried about this. It also would have jeopardized the nation's $1.8 billion production of stone fruit."

Travis saluted growers in the quarantined area for their courage. Government efforts to eradicate plum pox in France failed, he noted, partially because growers there would not do what was needed. "Growers here were compensated, but there were things that could not be accounted for, like people losing their peach markets," he said. "There were huge sacrifices and shifts in business.

"The impact on the affected growers and their families was enormous. It has been 10 years since they were able to grow peaches. Some switched to apples and will never grow peaches again."

Bruce McPheron, dean of Penn State's College of Agricultural Sciences, said the plum pox effort illustrates how the state's land-grant university can mobilize research and generate practical knowledge for the public good. "To rid the state of plum pox virus while assisting growers in maintaining their operations required the expertise of Penn State plant pathologists, horticulturists, agricultural economists and extension educators, working in partnership with the state and federal agriculture departments and the fruit industry," he said. "This successful collaboration can serve as a blueprint for future plant- and animal-disease outbreaks."